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|
## experimental compiler to translate programs of a generic
## expression-oriented language 'lambda' into mu
scenario convert-lambda [
run [
local-scope
1:address:array:character/raw <- lambda-to-mu [(add a (multiply b c))]
2:array:character/raw <- copy *1:address:array:character/raw
]
memory-should-contain [
2:array:character <- [t1 <- multiply b c
result <- add a t1]
]
]
def lambda-to-mu in:address:array:character -> out:address:array:character [
local-scope
load-ingredients
out <- copy 0
tmp:address:cell <- parse in
out <- to-mu tmp
]
# 'parse' will turn lambda expressions into trees made of cells
exclusive-container cell [
atom:address:array:character
pair:pair
]
# printed below as < first | rest >
container pair [
first:address:cell
rest:address:cell
]
def new-atom name:address:array:character -> result:address:cell [
local-scope
load-ingredients
result <- new cell:type
*result <- merge 0/tag:atom, name
]
def new-pair a:address:cell, b:address:cell -> result:address:cell [
local-scope
load-ingredients
result <- new cell:type
*result <- merge 1/tag:pair, a/first, b/rest
]
def is-atom? x:address:cell -> result:boolean [
local-scope
load-ingredients
reply-unless x, 0/false
_, result <- maybe-convert *x, atom:variant
]
def is-pair? x:address:cell -> result:boolean [
local-scope
load-ingredients
reply-unless x, 0/false
_, result <- maybe-convert *x, pair:variant
]
def set-first base:address:cell, new-first:address:cell -> base:address:cell [
local-scope
load-ingredients
pair:pair, is-pair?:boolean <- maybe-convert *base, pair:variant
reply-unless is-pair?
pair <- put pair, first:offset, new-first
*base <- merge 1/pair, pair
]
def set-rest base:address:cell, new-rest:address:cell -> base:address:cell [
local-scope
load-ingredients
pair:pair, is-pair?:boolean <- maybe-convert *base, pair:variant
reply-unless is-pair?
pair <- put pair, rest:offset, new-rest
*base <- merge 1/pair, pair
]
scenario atom-is-not-pair [
local-scope
s:address:array:character <- new [a]
x:address:cell <- new-atom s
10:boolean/raw <- is-atom? x
11:boolean/raw <- is-pair? x
memory-should-contain [
10 <- 1
11 <- 0
]
]
scenario pair-is-not-atom [
local-scope
# construct (a . nil)
s:address:array:character <- new [a]
x:address:cell <- new-atom s
y:address:cell <- new-pair x, 0/nil
10:boolean/raw <- is-atom? y
11:boolean/raw <- is-pair? y
memory-should-contain [
10 <- 0
11 <- 1
]
]
def first x:address:cell -> result:address:cell [
local-scope
load-ingredients
pair:pair, pair?:boolean <- maybe-convert *x, pair:variant
reply-unless pair?, 0/nil
result <- get pair, first:offset
]
def rest x:address:cell -> result:address:cell [
local-scope
load-ingredients
pair:pair, pair?:boolean <- maybe-convert *x, pair:variant
reply-unless pair?, 0/nil
result <- get pair, rest:offset
]
scenario cell-operations-on-atom [
local-scope
s:address:array:character <- new [a]
x:address:cell <- new-atom s
10:address:cell/raw <- first x
11:address:cell/raw <- rest x
memory-should-contain [
10 <- 0 # first is nil
11 <- 0 # rest is nil
]
]
scenario cell-operations-on-pair [
local-scope
# construct (a . nil)
s:address:array:character <- new [a]
x:address:cell <- new-atom s
y:address:cell <- new-pair x, 0/nil
x2:address:cell <- first y
10:boolean/raw <- equal x, x2
11:address:cell/raw <- rest y
memory-should-contain [
10 <- 1 # first is correct
11 <- 0 # rest is nil
]
]
def parse in:address:array:character -> out:address:cell [
local-scope
load-ingredients
s:address:stream <- new-stream in
out, s <- parse s
]
def parse in:address:stream -> out:address:cell, in:address:stream [
local-scope
load-ingredients
c:character <- peek in
pair?:boolean <- equal c, 40/open-paren
{
break-if pair?
# atom
b:address:buffer <- new-buffer 30
{
done?:boolean <- end-of-stream? in
break-if done?
# stop before close paren
c:character <- peek in
done? <- equal c, 41/close-paren
break-if done?
# stop at spaces after consuming them
c <- read in
done? <- equal c, 32/space
break-if done?
b <- append b, c
loop
}
s:address:array:character <- buffer-to-array b
out <- new-atom s
}
{
break-unless pair?
# pair
read in # skip the open-paren
out <- new cell:type # start out with nil
# read in first element of pair
{
done?:boolean <- end-of-stream? in
break-if done?
c <- peek in
close-paren?:boolean <- equal c, 41/close-paren
break-if close-paren?
first:address:cell, in <- parse in
*out <- merge 1/pair, first, 0/nil
}
# read in any remaining elements
curr:address:cell <- copy out
{
done?:boolean <- end-of-stream? in
break-if done?
c <- peek in
close-paren?:boolean <- equal c, 41/close-paren
break-if close-paren?
first:address:cell, in <- parse in
new-curr:address:cell <- new-pair first, 0/nil
curr <- set-rest curr, new-curr
curr <- rest curr
loop
}
}
]
scenario parse-single-letter-atom [
local-scope
s:address:array:character <- new [a]
x:address:cell <- parse s
s2:address:array:character, 10:boolean/raw <- maybe-convert *x, atom:variant
11:array:character/raw <- copy *s2
memory-should-contain [
10 <- 1 # parse result is an atom
11:array:character <- [a]
]
]
scenario parse-atom [
local-scope
s:address:array:character <- new [abc]
x:address:cell <- parse s
s2:address:array:character, 10:boolean/raw <- maybe-convert *x, atom:variant
11:array:character/raw <- copy *s2
memory-should-contain [
10 <- 1 # parse result is an atom
11:array:character <- [abc]
]
]
scenario parse-list-of-two-atoms [
local-scope
s:address:array:character <- new [(abc def)]
x:address:cell <- parse s
10:boolean/raw <- is-pair? x
x1:address:cell <- first x
x2:address:cell <- rest x
s1:address:array:character, 11:boolean/raw <- maybe-convert *x1, atom:variant
12:boolean/raw <- is-pair? x2
x3:address:cell <- first x2
s2:address:array:character, 13:boolean/raw <- maybe-convert *x3, atom:variant
14:address:cell/raw <- rest x2
20:array:character/raw <- copy *s1
30:array:character/raw <- copy *s2
memory-should-contain [
# parses to < abc | < def | 0 > >
10 <- 1 # parse result is a pair
11 <- 1 # result.first is an atom
12 <- 1 # result.rest is a pair
13 <- 1 # result.rest.first is an atom
14 <- 0 # result.rest.rest is nil
20:array:character <- [abc] # result.first
30:array:character <- [def] # result.rest.first
]
]
scenario parse-list-of-more-than-two-atoms [
local-scope
s:address:array:character <- new [(abc def ghi)]
x:address:cell <- parse s
10:boolean/raw <- is-pair? x
x1:address:cell <- first x
x2:address:cell <- rest x
s1:address:array:character, 11:boolean/raw <- maybe-convert *x1, atom:variant
12:boolean/raw <- is-pair? x2
x3:address:cell <- first x2
s2:address:array:character, 13:boolean/raw <- maybe-convert *x3, atom:variant
x4:address:cell <- rest x2
14:boolean/raw <- is-pair? x4
x5:address:cell <- first x4
s3:address:array:character, 15:boolean/raw <- maybe-convert *x5, atom:variant
16:address:cell/raw <- rest x4
20:array:character/raw <- copy *s1
30:array:character/raw <- copy *s2
40:array:character/raw <- copy *s3
memory-should-contain [
# parses to < abc | < def | < ghi | 0 > > >
10 <- 1 # parse result is a pair
11 <- 1 # result.first is an atom
12 <- 1 # result.rest is a pair
13 <- 1 # result.rest.first is an atom
14 <- 1 # result.rest.rest is a pair
15 <- 1 # result.rest.rest.first is an atom
16 <- 0 # result.rest.rest.rest is nil
20:array:character <- [abc] # result.first
30:array:character <- [def] # result.rest.first
40:array:character <- [ghi] # result.rest.rest
]
]
|